Field of the Invention
The present invention relates to a solid-state image sensor and a camera.
Description of the Related Art
Japanese Patent Laid-Open No. 2007-335723 describes a non-circular microlens. More specifically, Japanese Patent Laid-Open No. 2007-335723 describes a solid-state image sensing element which arranges a microlens having an almost circular shape in a plan view in the central portion of a light-receiving region and arranges a microlens having a teardrop shape in a portion away from the central portion of the light-receiving region. The teardrop shape has a long axis and a short axis, and its portion having the maximum width in a direction parallel to the short axis is close to a central portion side in the light-receiving region (FIG. 2, and paragraphs 0021 and 0022 of Japanese Patent Laid-Open No. 2007-335723). The direction of the long axis matches a direction of a straight line passing through the central portion of the light-receiving region. The teardrop shape is decided in accordance with a distance from the central portion of the light-receiving region.
An inventive concept described in Japanese Patent Laid-Open No. 2007-335723 can be understood to decide the basic shape of the microlens first, and then decide the shape of each microlens by rotating the basic shape in accordance with a position where each microlens should be arranged. According to the inventive concept described in Japanese Patent Laid-Open No. 2007-335723, the microlenses equal to each other in the distance from the central portion are understood to have rotation symmetry. However, when the plurality of microlenses each having a rotation-symmetric shape are arrayed in the positions equal to each other in the distance from the central portion, there are more gaps than in arraying a plurality of circular microlenses. This may reduce light collection efficiency.